Sizing compositions and yarn sized therewith



Patented May 27;, 1947 SIZING COMPOSITIQNS AND YARN SIZED THEREWITE Walter R. Haefele, Seaford, Del., assignor to E. I. do Pontde Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application July 29, 1943, Serial No. 496,621

11 Claims. (Cl. 260-32) This invention relates to new and improved hydroxylated polyvinyl resin compositions, and

more particularly to a new polyvinyl alcohol sizing composition which is particularly useful for the sizing of water-insensitive yarns, and to the yarns sized therewith.

The term hydroxylated polyvinyl resin" as used herein is intended to cover any water-sensitive (soluble or dispersible in water) polyvinyl compound in which 1% to 50% of the carbon atoms in the polyvinyl chain are attached to hydroxyl groups.

For convenience, and without intending to limit the scope of the invention, the invention will be described in connection with a water-sensitive (soluble or dispersible in water), partially saponifled polyvinyl acetate, known in the trade as polyvinyl alcohol."

Water-sensitive polyvinyl alcohols possess certain properties which make them admirably suitable fo sizing of yarns, particularly water-insensitive yarns such as the nylon yarns of the market.

However, such polyvinyl alcohols are so watersensitive (dissolve or disperse in water) that when yarn sized therewith is run through a humidified area in order to soften the yarn at the moment of knitting, the size becomes gummy, fouls the needles and sinkers of the knitting machine, produces knitted fabrics of poor quality, and ultimately stops the machine. It is known that the water-sensitivity of polyvinyl alcohols can be modified by boric acid, and a. composition consisting of a partially saponified polyvinyl acetate with a substantial but minor proportion of boric acid used for sizing water-insensitive yarns, such as the nylon yarns of the market, has given very satisfactory results" even for the critical knitting of full-fashioned hosiery. The function of the boric acid is to lower and control the water-sensitivity of the water-soluble or water-dispersible polyvinyl alcohol. Borlc acid is a critical material and the shortage thereof is likely to increase and approach the point where it will not be available for these purposes. This can militate against the efllcient use of whatever yarn may be needed for critical and vital knitted fabrics.

An object of this invention is to modify the water-sensitivity of water-soluble or water-dispersible hydroxylated polyvinyl resin without the use of boric acid. .Another object of this invention is to provide a new and improved water-sensitive hydroxylated polyvinyl resin sizing composition in which the water-sensitivity of the hydi'oxylated polyvinyl resin is modified to such a degree that the composition can be satisfactorily used even for the critical knitting of full-fashioned hosiery. A specific object of this invention is to provide a new and improved polyvinyl alcohol sizing composition. Other and additional obiects will become apparent hereafter.

The objects are accomplished, in general, by modifying the water-sensitivity of polyvinyl alcohol with barium chloride.

The following examples are typical embodiments of the invention, and it is to be understood that the invention is not restricted to the specific details thereof; the parts. proportions and per-.

centages being by weight:

Example I A composition consisting of the following ingredients in the proportions set forth is prepared in any convenient manner:

Grams Partially saponlfied polyvinyl acetate (viscosity 5) (sap. No. 48) 12 Barium chloride (Bach) 4 Water a 168 Hexamethylene adipamide yarn having a denier of 30, a filament count of 10 and a twist of 30 turns is sized with this composition in any of the well-known ways to leave on the final yarn a 3.7% size composition. After the usual technical conversion treatment to form it into a package suitable for knitting, it is knit into full-fashioned hosiery fabric. It will be found that the yarn runs very well, that the needles and sinkers are free of deposits, and that the stitch formation of the fabric is quite good. It will be further found that the fabric shows excellent snag-resistance in the usual processing steps and that the size is readily removed by washing in hot water or in hot soapy water. A v

Example II A composition consisting of the followingfin-w gredients in the proportions set forth is prepared in any convenient manner:

' Grams' Partially saponified polyvinyl acetate (viscosity 6) (sap. No. 10 Barium chloride (BaCla) 1.7 Water 292* Yarn similar to that used in Example I is sized with this composition in any of the well-known.

ways to leave on the final yarn 3.9% size com.-

position. After the usual technical conversion, treatment to form it into a package suitablafor knitting, it is knit into full-fashioned hosiery I fabric. The yarn runs quite well, the needles] and.

Erample III A composition consisting of the following ingradients in the proportions set forth is prepared in any convenient manner:

Grams Partially saponified polyvinyl acetate (viscosity' (sap. No. 140) Barium chloride (BaClz) 0.9 Water 80 Yarn similar to that of Example I is sized with this yarn in conventional manner to leave on the yarn 5% size composition and the sized yarn formed in the known manner into a package suitable for knitting. When subsequently knitted into full-fashioned stockings, the needles and sinkers show no deposits, the knitting step proceeds well and the fabric has satisfactory snagresistance. Barium chloride seems to be unique among inorganic salts in its ability to lower and control the water-sensitivity of polyvinyl alcohol. None of the related halide salts produces this effect in any comparable degree and no other salt is known which produces the effect. It is difficult to exalain why this compound, so different in its normal properties from boric acid, should be a, satisfactory substitute for it in these compositions.

While a preference has been. shown for specific amounts of barium chloride based on the polyvinyl alcohol, it will be understood that variations within limits are possible. Generally speaking. quantities of 5% to 40%. and preferably to 35%, of barium chloride based on the polyvinyl alcohol will give quite satisfactory results.

In the foregoing examples, preference has been shown for a specific partially saponifled vinyl acetate which is soluble or emulsiflable in water and which is known in the trade as "polyvinyl alcohol. The invention, however, is not restricted to such specific polyvinyl alcohols. Gengrams of potassium hydroxide required to completely saponify one gram of the sample.

The partially saponified polyvinyl acetate may have viscosities of 1.5 to 20 centipoises, and preferably 4 to 6 centlpoises, the viscosity being determined on a 4% aqueous solution at 20 C. using a Hoeppler viscosimeter.

The composition is conveniently applied to the yarn by means of a bobbin to bobbin" type machine in which the yarn passes over a rotating cylindrical roll dipping in the sizing composition. The speed at which the roll rotates will vary with the speed of the yarn and will depend on the amount of the composition which it is desired to apply to the yarn. The composition also can be applied by passing the yarn in a continuous fashion through a bath containing the composition or by dipping loosely wound skeins therein, followed by wringing to remove excess liquor. Any other suitable method may be employed for applying the composition. For example, the composition may be sprayed on a moving strand of y It will be obvious to one skilled in the art that the sizingcompositions of this invention can be applied by conventional methods from an aqueous solution or dispersion of any desirable concentration to yield on the yarn a coating of any reasonable thickness. Solutions of 2% to 12% total solids content are preferred, depending. as is known, on such factors as the denier and fllament count of the yarn, its water-sensitivity, the

. rate of travel of the yarn during application of erally speaking, any water-sensitive polyvinyl compound in which 1% to and preferably 20% to 50%, of the carbon atoms in the polyvinyl chain are attached to hydroxyl groups (such compounds being herein referred to as hydroxylated polyvinyl resin) can be used. As illustrative examples of hydroxylated polyvinyl resins which can be used are the partial esters of polyvinyl alcohol such as the partial acetates, the partial propionates, the glycolic acid esters, the partial formates, and the partial lactates; the partial others 01 polyvinyl alcohol such as the glycol ethers, the glycolic acid ethers, the methyl ethers, and the ethyl others; the partial acetals of polyvinyl alcohol such as the partial formal, the partial acetal, the partial glyoxal, the partial propional, and the partial butyral; the partial ketals of polyvinyl alcohol such as the ethylmethyl ketal.

Although partially saponified polyvinyl acetates having saponification numbers from 40 to 150 are particularly useful, partially saponified polyvinyl acetates having saponification numbers oi between 10 and 300, such as 40 to 200,017 even somewhat lower than 10 or higher than 300, may be used to advantage. Saponiiication numbers of the partially saponified polyvinyl acetate, as used herein, are defined as the number of millithe size, the temperature of the sizing composition, and of the drying conditions, and the amount of size desired on the yarn. It will be obvious,

too, that the amount of size desired on the yarn will vary with these or 'similar factors. Generally, a coating on the yarn of 1% to 6% is preferred.

For reasons of simplicity, the invention has been discussed specifically in terms of polyhexamethylene adipamide yarn since that is the common nylon yarn of the market. The invention obviously embraces other synthetic linear polyamide yarns, as well as related synthetic linear polymer yarns, such, for example, as those derived from polymerizable mono amino carboxylic acids or their amide-forming derivatives and.

those derivedf'rom the reaction of suitable diamines with suitable dicarboxylic acids or amideforming derivatives of dibasic carboxylic acids disclosed in U. S. Patents Nos. 2,071,250, 2,130,523 and 2,130,948. Without limiting the broad and general definitions of "nylon" as used elsewhere in patents or literature, the synthetic linear polyamides herein disclosed are, defined as set forth in U. S. Patent 2,359,877, i. e. a synthetic linear polycarbonamide wherein the average number of carbon atoms in the segments of the chains separating the amide groups is at least two.

The invention is additionally applicable to any water-insensitive synthetic linear polymer yarn since the compositions employed in this invention adhere well to these yarns in contrast to the more well-known compositions. By the term waterinsensitive," it is meant that the individual filaments of the yarn absorb less than 10% of their weight of water at 25 C. and 100% relative humidity. Examples of such polymers are the vinyl chloride-vinyl acetate. interpolymers, polymer- .ized methyl methacrylate or polymerized ethyl methacrylate, polyvinyl chloride, chlorinated The composition of this invention is particularly useful as a size because of the ease of application to the yarn and ease of removal from the resulting fabric, and further because it deposits 9. solid coating that is not quickly dissolved whereby the sized yarns runthrough a water-wet wick or other humidifying treatment without becoming gummy and without fouling the needles and sinkers of the knitting machine.

The size of this invention adheres well to the water-insensitive yarn while possessing other qualities desired in a size for yarn to be used in the knitting of full-fashioned hosiery. Yarn sized with the size of this invention knits very well and produces sheer full-fashioned stocking fabrics which are relatively free of snags and pull threads. This size minimizes edge-rolling characteristics and thus assists in the more economical production of sheer knitted full-fashioned hosiery. The size of this invention causes very little wear and corrosion of the needles and sinkers of the knitting machine. In knitting yarns sized with compositions of this invention, the stitch formation is very good and may be maintained uniform over long periods of time.

Though the composition of this invention is basically an excellent full-fashioned knitting size for water-insensitive yarns, it is equally useful for circular knitting of similar or heavy fabrics from similar or heavy denier yarns, including monoflls, and may also be used to advantage with other structures, such as film's, staple fibers, spun yarn, mixed yarn, ribbons, etc. Also, the composition is useful as a size for water-insensitive weaving yarns.

The modification of water-sensitive polyvinyl alcohols and derivatives thereof to apparent insolubility or apparent slow solubility, as herein described, can be employed for uses other than for sizes. For example, polyvinyl alcohol flake or powder, produced from the composition of this invention, is very free-running even in reasonably humid atmospheres and is well suited for such operations as injection molding. Films cast from such a composition show markedly reduced tendency to stick together. A wall surfaced with such composition well resists marks from momentary contact of the hand. A surface painted with fugitive colors using this composition as a vehicle resists removal in humid atmospheres but can be easily removed when desired. Other related uses for the composition will readily occur to those skilled in the art.

Since it is obvious that many changes and modifications can be made in the above-described details without departing from the nature and spirit of the invention, it is to be understood that the invention is not to be limited thereto except as set forth in the appended claims.

I claim:

1. A yarn-sizing composition depositing a solid coating that permits yarn sized therewith to run through a, water-wet wick or other humidifying treatment without becoming gummy and without fouling the needles and sinkers of the knitting machine and comprising an aqueous solution of a water-sensitive hydroxylated polyvinyl resin and 5% to 40% of an agent to reduce the watersensitivity of said hydroxylated polyvinyl'resin, said agent consisting of barium chloride, the percentage being by weight and based on the hydroxylated polyvinyl resin, and the total solids content being from 2% to 12% of the composition.

, 6 2. A yarn-sizing composition depositing a solid coating that permits yarn sized therewith to run through a water-wet wick or other humidifying treatment withoutbeccming gummy and with-- out fouling the needles and sinkers of the knitting machine and comprising an aqueous solution of a water-sensitive hydroxylated polyvinyl resin and 15% to 35% of barium chloride, the percentag being by weight and based on the hydroxylated polyvinyl resin, and the total solids content being from 2% to 12% of the composition.

3. A yarn-sizing composition depositing a solid coating that permits yarn sized therewith to run through a water-wet wick or other humidifying treatment without becoming gummy and without fouling the needles and sinkers of the knitting machine and comprising an aqueous solution or a. partially saponifled polyvinylacetateand 5% to 40% of an agent to reduce the watersensitivity of said polyvinyl acetate, said agent consisting of barium chloride, the percentage being by weight and based on the polyvinyl acetate, and the total solids content being from 2% to 12% of the composition.

4. A yarn-sizing composition depositing a solid coating that permits yarn sized therewith to run through a water-wet wick or other humidifying treatment without becoming gummy and without fouling the needles and sinkers of the knitting machine and comprising an aqueous solution of a partially saponifled polyvinyl acetate and 15% to 35% of barium chloride, the percentage being by weight and based on the polyvinyl acetate, and the total solids content being from 2% t 12% of the composition.

5. A yarn-sizing composition consisting of the following ingredients in the following approximate proportions:

Grams Partially saponifled polyvinyl acetate (Viscosity 5) (Sap. No. 46)

Barium chlorid (Bach) Water 6. A yarn-sizing composition consisting of the following ingredients in the following approximate proportions:

Grams Partially saponified polyvinyl acetate (Viscosity 6) (Sap. No. 140) Barium chloride (Bach) 1.! Water- 292 '7. A yarn-sizing composition consisting of the following ingredients in the following approximate proportions:

Grams Partially saponifled polyvinyl acetate (V cosity 5) (Sap. No. 140) 10 Barium chloride (Bach) 0.9 Water 8. A water-insensitive yarn having a coating of a size permitting the yarn to run through a water-wet wick or other humidifying treatment without becoming gummy and without fouling the needles and sinkers of the knitting machine and comprising a water-sensitive hydroxylated polyviny1 resin and 5% to 40% of an agent to reduce the water-sensitivity of said hydroxylated polyvinyl resin, said agent consisting of barium chloride, the percentage being by weight and based on the hydroxylated polyvinyl resin.

9. A water-insensitive yarn having a coating of a size permitting the yarn to run through a water-wet wick or other humidifying treatment without becoming gummy and without fouling the needles and sinkers of the knitting machine and comprising a partially saponified polyvinyl acetate and 5% to 40% of an agent to reduce the water-sensitivity of said polyvinyl acetate, said agent consisting of barium chloride, the percentage being by weight and based on the polyvinyl acetate.

10. A synthetic linear polyamide yam formed of a synthetic linear polycarbonamide wherein the average number of carbon atoms in the segments of the chain separating the amide groups is at least two and having a coating or a size permitting the yarn to run through a water-wet wick or other humidii'ying treatment without becoming gummy and without fouling the needles and sinkers of the knitting machine and comprising a water-sensitive hydroxylated polyvinyl resin and 5% to 40% of an agent to reduce the watersensitivity 01' said hydroxylated polyvinyl resin, said agent consisting oi. barium chloride. the percentage being by weight and based. on the hydroxylated polyvinyl resin.

11. A synthetic linear polyamide yam formed 8 of a synthetic linear polycarbonamide wherein the average number 01' carbon atoms in the segments of the chain separating the amide groups is at least two and having a coating of a size permitting the yarn to run through a water-wet wick or other coming gummy and without fouling the needles and sinkers or the knitting machine and comprising a partially saponified polyvinyl acetate and to 40% of an agent to reduce the watersensitlvity of said polyvinyl acetate, said agent consisting oi barium chloride, the percentage being by weight and based on the polyviny acetate. 7

e WAL'I'ER, R. HAEFELE.

REFERENCES CITED The following references are of record in the file or this patent:

UNITED STATES PATENTS Number Name Date 2,246,915 Dangelmajer June 24, 1941 2,300,074 strain Oct. 27, 1942 humidifying treatment without be- 

